Polishing machine



Sept. 1956 IEPACKOR 2,761,255

POLISHiNG MACHINE Filed 001,. 2, 1953 8 Sheets-Sheet 4 21/ f2? Vania?".FM/L LDACKOE:

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Sept. 4, 1956 E. DACKOR POLISHING MACHINE 8 Sheets-Sheet 5 Filed Oct. 2,1953 [Hz En [27F ZM/L DA 0260B Sept. 4, 1956 a DACKOR POLISHING mums 8Sheets-Sheet 6 Filed Oct. 2 1953 km. m 9mm MQQ Sept. 4, 1956 E. DACKOR2,761,255

' POLISHING MACHINE Filed Oct. z, 1953 a Sheets-Sheet a F fi b m H fi nA w E D 3N V. u n M u. fr H. 4 Q a w l M l w w Mn. NR. 7 l A NE maw wIlll III I J m; m Ex p I swwmw if K m3 M ow 8 MG v \w% 3w NW w N v w MNMNMN w m an R6 u. I? Sm. WWW l a owh m @NE pieces.

.a multiplicity of workpi'e ces simultaneously mounted on a turret-typerotary mechanism.

,toprovigle a new and improvedtturret typepolishing .chine wherein anumber of workpieces ,suchas t bine 2,761,255 POLISHING MAcuiNr;

Emil 'Daclror, Euclid, Ohio, assignor to Thompson Products,:Inc.,Cleveland, Ohio, aIcorporation .of Ohio Application Octoher 2, 1953,Serial No, 3 83,8519 12 Claims. (81 51-151) The present inventionrelates to a polishing machine.

and more particularly relates to a machine Operable to eiiiciently,economically and rapidly polish a workpiece such as a turbine 'blade orbucket or vane or the likehaving oppositely disposed complex arcua tesurfaces which may be of airfoil configuration or the like.

plurality of polishing units are mounted on a rotatable turret and eachcarries a separate workpiece for simultaneously polishing the surfacesof a plurality of work- At an operator station which is a preselectedposition about the rotatable turret, a finished and polished workpieceis ejected or released :f rom each successive polishing unit and a newworkpiece to bepolished inserted into, each successive unit forpolishing.

A Before the system of the above-mentioned patent was developed,polishing of such complex arcuate sur faceson oppositely disposed facesof a workpiece suchas tufbine blades, buckets or vanes was effected byha lidl olishi ng "methods which necessarily involved long and tediousarid.

@XPfinsive working and provided no assurance of-iiniforrnity of thefinished workpieces. The system the aforementioned patent resolved thatV c vided a machine readily operable to economically polish i ue td ityof poli machinealso included a plural tern of the present invention,however, provides (an .1

e re is i st n e h n sm e e t e sys e 59 th ehsve-ms e Pat n It therefore, an important feature of the present-inentiq to pr v d a ne nimPmWdpd h n mai ings- Y it, ,is another important feature of thepresent invention ta hes of n 9 blade ha i ns t rtiuss r tqmnle ar s s ae m be reli h -susta n ewnomically and simultaneously.

-Another ,object and feature of the,presen t inver tion is .to provide apolishing system ,for a-workpiecesuch asga turbine blade wherein theworkpiece oscillated between aupair. of relatively stationarypolishisreciprocatedtand ing members by a workpiece holding memben andcoperatingdevice. I

Still another object of the present invention is to provide a polishingmechanism of the horigontally rotatable turret-type wherein a number ofpolishing units are carried one turrettype drive mechanism and carryingne'ch- States Patent reeling mechanism and polishing Patented Sept. 4,1956 anism and wherein the drive mechanism and carrying mechanism is newandimproved.

improved power take oIf system.

Still another object of the present invention is to provide a system ofthe class described wherein each polishing unit is provided with a pairof polishing belts each trained over a polishing pressure pad carriedbyan improved pad-carrying mechanism.

Still another object of the present invention is to provide each of thepolishing units with a new and improved pad operator mechanism and a newand improved work clamping jaw operator mechanism.

Still another object of the present invention is to provideeach of thepolishing units with an improved independent jaw-operating mechanism andindependent p a d operator mechanism. li l A still further object of thepresentinvention is to provide each of the polishing units with a shockmounting operator system for [each of the pa dfcarrying mechanisms. l iA still further object of the present inventionis 10 provide each ofthepolishing units withadiniproved polishinghelt reeling mechanism.

" Yet another object of the present invention is to pro- 1 i PE PI WSvide each ofthe polishing units with a raw rele e m sha m A still fnrther object of the present invention is to provide a new and improvedpolishing helt lockin g mechanism Still another object of the video. nowand improved P e ent wsnfien i torred s r n operat n rnechanism for bothreciprocatingdand oscillating tlie workpiece.

Still another object of the present invention is to provide a new andimproved cam and follower system for opei'atinga polishing machine ofthe class described in a new and improved manner. V I

.Still other objects, features and advantages of the present inventionwill readily present themselves .totho se skilled in the art from theforegoing andltfrom the following detailed description and from theaccompanying sheets ,of drawings illustrating a preferred embodiment ofthe present invention and forming an integral pa rt of thisSpecification, in whichlike referencetnumerals,refer to like parts, andin which: q i

Figure 1 is a top plan View, partially in diagrammatic illustration,illustrating a preferred emnqdnnent of the present invention;

Figure 2 is apartial sectional view of the system of Figure 1 is takenalong the line I I--II of Figure I Figure Bis a side elevational view ofa single polishing unit embodying the principles of the presentinvention as viewed along the line lIIf-lll of Figure 1 Figure 4 is afront elevational viewofa single polishing unit embodyingnthe principlesof the present inventiongas viewed along the line IV- -IV of Figure 1;

Figure 5 is a top plan view, partially in section, of the cam and camfollower system and polishinggpad. carrying and operatormechanism asviewed along the line "V -V of Figure 3;

Eigure 6 is an enlarged front elevationaltview of the pad operatormechanismtaken'along the line VlI-VI of Figure 3;

Figure 7 is an enlarged front elevational view of the work-carrying ramand jaw and oscillator mechanism taken along the line VII-VII ofFigure-3;

Figure 8 is a sectionalview of aportion of the .jaw release mechanismtaken along the line .VIII*VIII of Figure Figure 9 is a bottom plan viewof the jaw mechanism and workpiece holder oscillating mechanism of thisembodiment of the present invention taken along the line IX-IX of Figure7.

There is illustrated in Figure 1, partially in diagrammaticillustration, a top plan View of a machine, indicated generally at l,embodying the principles of the present invention. The machine 1 ispreferably a turrettype machine carrying a number of polishing units 2a,2b, 2c, 2d and 2e. The number of these units on the machine 1 is notcritical and may be as large a number as desired. The machine 1 of thepresent invention has been i1- lustrated with five such units generallyidentified by the numeral 2, mounted on a pentagonal turret head 3 forsubstantially horizontal rotation about the center of the machine. Therotating head or turret table 3, of course, need not necessarily bepentagonal but it is preferred that the turret table 3 have a regularconfiguration which may be round or have any number of sides preferablycorresponding to the number of polishing units such as the units 2a, 2b,2c, 2d and 2e supported thereon and rotated thereby about the center ofthe polishing machine.

The turret mechanism 3 includes a turret table-type device 301 which iscarried by a supporting unit 302 to rotate the polishing units about thecenter of the machine and over a preferably substantially circularcoolant tank 4. The coolant tank 41, as illustrated, has a bottom wall401 with an outside diameter suflicient to extend substantially to theradial extremity of the units 2 and there has an upturned flange orperipheral side wall 402. The tank structure 4 may, of course, have anydesired configuration and construction but the above is preferred whenemploying a coolant with the system of this invention.

The turret mechanism 3 including the turret table structure 3M and thesupporting structure 302 may be best understood by reference to Figure2. As shown in this figure, the polishing unit 2a, along with the otherpolishing units which are not shown in this figure of the drawings, issupported by the side plate 3% of the rotary section 301 of the turretto which it is secured by any convenient means such as bolts or screwsor studs 304. Stand-off spacers 3%, which may be washers or the like,properly space the polishing units, such as the unit Zn, from the sidewalls of the rotary section Etll of the turret mechanism 3. Individualpolishing unit drive motors 2% are secured through base plates or thelike 202 to a turret table plate 3% by means of bolts or the like 397.The turret table plate 3% forms the upper face of the rotating section331 of the turret mechanism 3 and is secured to the side walls 3% by anyconvenient means such as welding or bolting or riveting or the like, andin this preferred embodiment of the present invention, as illustrated inFigure 2, is secured to the side walls 303 and supported thereon throughangle iron members or the like. The rotary turret table section 3% isalso provided with a bottom plate 363'? which is secured to the sidewall members 3% in a like manner to the manner of securing the tableplate 3% to the side walls 393.

In the geometric center of the turret assembly 3 and particularlythrough the rotary turret section 3631, a space bounded by internalwalls 3tl9 is provided for a supporting column 314) which extends fromthe lower extremity of the base section 302 to the very top of themachine. This column 310 is preferably a hollow one and carries, throughthe interior thereof, numerous of the electrical power leads and controlleads for the mechanism and sys tem of the present invention. inaddition, thrust-type roller bearing assemblies 311 and 312 are securedto the column 310 and the upper and lower turret table plates 306 and308. The thrust bearing assemblies 311 and 312 are preferablyroller-type bearings, as illustrated, but: may be any other desired typeof thrust bearing, and while they are preferably securely fixed to theupper and lower turret table plates 3% and 308 by machine screws or thlike 313, the inner races of the thrust bearings are adjustably securedto the hollow supporting column 310 in any convenient manner such as bypositioning nuts or the like 314 threadably engaging the supportingcolumn 310 and positioning the bearing assemblies 311 and 312.

The pedestal or base section 3&2 of the turret assembly includes anappropriate support 320 at the lower extremity thereof for the hollowsupporting column 310. The pedestal or base section 302 also houses therotary power mechanism for rotating the turret assembly about the centerof the machine, about the supporting column 310 on the thrust bearings311 and 312. The rotary power mechanism itself includes a convenientdriving machine such as an electric motor 32ft which is fixedly securedby a mounting base member or the like 322 to a cross frame 323 securedat its opposite ends to the side wall 324 which is reinforced byappropriate members 325.

Above the turret rotating drive motor 321 the supporting bracket 323carries a journal assembly are housing a worm gear or the like 327 and apinion shaft 328 mounted in appropriate bearings 329. in the region ofits lower end, the pinion shaft 328 has an appropriate gear 339 securedthereto to mesh with the worm gear 327. The motor 321 and the worm 327each carry sprocket wheels 331 and 332, respectively, which areappropriately interconnected by a sprocket chain 333. Rotational powerproduced at the motor 321, which is preferably an electric motor,imparts rotary motion to the worm gear 327 which in turn drives the gear33d and the pinion shaft 328. At its upper end the pinion shaft 328carries a pinion gear which mates with a rim gear 335 or the like. Thisrim gear is securely fastened to the lower turret plate 3% by anyconvenient means such as a bolt or machine screw or the like 336 and isconcentric with the supporting shaft Bill. Thus, rotatably driving thepinion shaft 325 rotates the pinion gear 334' and thereby drives thegear and the rotary turret head 301, the rotary turret head rotatingabout the supporting column 3ft on bearings 311 and 312.

Additional supporting structure is provided within the pedestal 302 by astructural plate member 337 which is secured peripherally within thepedestal or base 392 and to the side wall structure 324 thereof carryinga bearing block 338 which supports the column 310 against distortionfrom the weight load thereon in compression. The structural plate 337also carries an additional supporting element 339 which operates tosupport and position tl 1 e journal housing 326 and thereby the pinionshaft 328.

In addition, the hollow supporting column 310, at its upper end, carriesan electrical power take-off system 350 for selectively providingelectrical power to the motors 201 of the polishing units 2. In highpower electrical applications it is preferred to use three phaseelectric power brought into the system on three leads, not shown. Eachof these leads would be brought through the hollow interior of thesupporting column 310 and one aiiixed, electrically, to each slip ringor electrical power take-up ring 351, 352 and 353, which are otherwiseinsulated by ring insulator members 354- from the remainder of thesystem. A set of three brushes 355, 356 and 357 are supported on acontact-carrying post 353 which is secured to the upper turret tableplate 306. The brushes 355, 356 and 357 are, of course, insulated fromthe carrying post 358.

Since each of the polishing units indicated generally by the numeral 2,is substantially identical to each of the other polishing units, it isnecessary to describe only one of the same in detail. The polishing unit2a will, therefore, be described in detail and this unit 2a is bestviewed in full in Figures 3 and 4 of the drawings. As statedhereinabove, Figure 3 is a side elevational view of a single completepolishing unit, the unit 2a, and Figure 4 is a substantially full frontelevational view of the same polish ing unit, the unit 2a.

The principal operating portions of the polishing unit r211 are .carried.by a

.- section for. the polishing unit ,pair of pulleys t2ti8and outputshaft 210 of :the'motor ztl predominantly in a one indicated generallyat 413. .;,-portions 414.facially engagepreferably-arerticallytmounted.i-fram or stand 203 which: is secured to:the-iurret .wau 303 .by .the bolts or screws/or studs 304. and spacedv.therefrom .by the .washersorthedike 3,95,;as described above. vAntupper padmember 204 supports a powendrivenram reciprocating mechanismindicated generally at 4, while a .lower pad member 205, on themainrframe 1support203 .carries the work holding andrammechanism-indicated ,generally at.5. Aramoscillating mechanism,vindicated generallyat .6, is secured to the upstanding: frame and support.2tl3 .below the mower-driven ram reciprocating .system 4 and.laterally immediately adjacenttto the work- ;.holding-mechanism .5 and:the pad member -205.

.In. addition, the PPOrtvmember 203 has .a lower-out- ,wardlytextendingflange v12.06 which:operably supports, a ijawn'elease or .work .holderrelease. operator mechanism 7, .apolishing surface padmembercarrying-mechanism 8 .vanda pad member retracting operator zmechanism19.

.A bracer and support membert207 (Eigure 4)- is secured fitothe forwardfaceofthe upper pad member'204 and .carries .a housing 401-,fr thepower-driven reeiproeator 2a. A ,shaft -402 is .journaled in .thehousing 401 and in the region of oneend thereof-has a pluralityofpulleys/103, .404 and 405 keyed thereon for rotation therewith, therotating force to ;be

utransmitted to the shaft 402by the pulleys 404- and. 405.

.Each of the pulleys 404 same diameter and are and .405 are ofsubstantiallythe coupled by belts or the like .406 and .407 to anotherpair of pulleys 208: and 209twhich-are to bedriven by the polishingunitmotor201. Thislatter 209 v are preferably coupled to the At theotherendof the shaft z402-a.crankdisc 408 is keyed. or "otherwise securedsthereto fortrotationrthereguideway409 and is longitudinally bored andthreaded for locking acceptance I of t the threaded end i 412 r of a.spindle A pair of separated shoulder opposite sides of the retainerand-spacer block 415 in the region of the head 416 of the spindle413.The spacer and retainer block 415:isi fixedly ,secured in any convenient-way409 nearest the center of the crank:disc 408. The

manner to theend of the crank head end 416 of the crank spindlez4l3 isproperly proporationed for manipulation by an. appropriate tool for con--venient rotation of the crank spindle413and thereby convenientincreasing and/ or decreasing of the spacing ofthe cross head 411fromthe ,centero'f the crank disc 408 along ethe track channel 410 ofthecrank way 409.

.A connecting rod 420 has one of its ends journaled on the'tcross headassembly 411 and retained thereon by a retainer screw such as a machinescrew 421 having an enlarged head section orwasher 422at the hea d toretain the connecting rod 420journaled onto an appropriately.configurated portion of the cross head assembly 411. At its other endthe elongated connecting rod 420 is journaled onto an appropriatelyconfigurated section of a-second :cross head 430 and retained thereon bya similarly appropriate retainerscrew 431 and washer orthe like 432.This second cross head assembly 430 is provided with 'an' end plate 433secured to the opposite end thereof from the connecting rod 420 by anyconvenient means such as 'another machine screw or the like 434 and isthereby constructed to track in an elongated opening 501 in the upperportion of the front face of the work-holding assembly 5. A secondspindle rod 502 threadedly engages the cross "head 430 andis alsoprovided with shoulder portions 5'03 ;at;its head end 504 to faciallyengage a retainer plate 505 1411, etc. and-thatthese two assemblies"work holder support about the axis of the secured .onto'th uppe e d ofthe wo k-ho dingearria assembly 5 immediatelyover the openingfill.

lttwill be appreciated that this preferred ernbodiment of thepresent-invention the upper end of the work hol ding assembly,Sincluding the opening 51and therassooiated crosshead 439 and spindlemember-.502, etc. closely ,resemble the crank-way 499 and itsassociatedcross head a e i t rconne te a pp ey ae and a lowerv ey e endby the connecting rod 420 having 'journaled on the cross head 411journaled on the cross head 430. Through operationw of thismechanism asthe shaft 402 is rotated by thepolishing unit motor 201 the work-holdingassembly ;5 ;is reciprocated, the amount of reciprocation, thatistheiam- 'plitude of the reciprocation, is controlled ,by the position ofthe cross head 411 with respect tothe-centenpfrthe crank disc 4%. Thisamplitude of reciprocationv is-tadjustably controlled by the spindle.4113. The vertical positioning of the work-holding assembly 5 may beadjusted also in a similar manner by rotatable manipulation ofrthespindle 502, the head end 504of which is also properly .coniigurated foracceptance of an appropriate :tool.

The work-holding, clamping and release mechanism: 5 which is in-partreciprocated by the mechanismA immediately above described, is supportedfrom the ;pad 205 for pivotal movement with respect thereto (Figures3and 9.). A work holder track assembly 510 has a; main track {bed memberfillprovided with a pair. of rearwardly extending ears 512 and 513 orthelike which arejournaled :ona pivot shaft or pin 516WhiChlS mountedthrough a -recess;212in the pad blockZllS. The recess 212 extends lessthanthefull distance between opposite sidesof :the block 205 therebyleaving pivot ears 213 and 2-14 thereon for acceptanceof the pivot shaft516. Sleeve members .215 and 2.16 are fitted into appropriate openingsin the ears 213and 214 and surround the shaft "516. Thcshaft 5ll6itselfmay be either secured1to the'pad 205 ,with the release mechanismjournaled "thereon or. secured to .the track assembly andijournaled in:the; pad block ears 213 and 214thus permitting pivotaLmovement of thework holder mechanism 5 with respect to the frame pivot shaft 516without opportunityfor the shaft 516 to become displaced.

This pivotal arrangement for the work holder:mecha nism 5 is provided topermit oscillation of the unit byrthe oscillator mechanism 6 asdescribed indetailbelow. Before examining the oscillator mechanism 6,however, detailed. discussion of the workholder mechanism 5 will besubstantially completed, atleast with respect to the reciprocatormechanism 4.

The work holder track assembly 510 which is pivotally =supported onthepivot shaft or pin 516 is principally constructed fromtthe main trackmember 511. The main track member 51-1 is substantiallychannel-shaped'having a central longitudinally extending channel 520therein bounded on three sides by inner faces of 'themain track element511. Buffer plates 521 and 522 are secured to the extreme front face ofthe main track element Sllatid project a short distance laterally overthe channel5 20 thus providing a positive track channel in the trackassembly 516). Bearing plates 52.3, 524, 525 and 526, which may beconstructed of oilless bronzeare secured to the main track member 511and form a major portion of the raceway therein. The work-holding,clamping and release mechanism 5 also includes the work carriageindbcated generally at 530. This carriageaSSEI istprovided with a housing531 having a flanged backface, including 1 the 1 laterally extendingflanges 532 and 533 which, track within the track-bed assembly 510 andare. reciprocable within the track bed as operated upon by thereciprocator mechanism 4.

As previously pointed out, the reciprocator=mechanisjn -4 acts upon thiscarriagemechanism 530'th1ough thezsystern above described v toreciprocate the carIiage SSOrmcluding the flanged housing 531substantially vertically in the track assembly 510 therefor.

Also as stated, the work-holding assembly is pivotally mounted to theframe pad 205 for oscillatory movement of the work holder in conjunctionwith and in cooperation with reciprocatory movement thereof. Thisoscillatory movement is provided to the work holder by an oscillatormechanism 6 which is best viewed in Figures 3, 4, 7 and 9. The readersattention, however, is principally directed to Figures 7 and 9 for thebest understanding of the oscillator mechanism 6.

A small pulley 463 (Figure 4) which is keyed to the shaft 402 drives abelt or the like 601 which in turn drives an oscillator mechanism drivepulley 662 keyed to an oscillator mechanism shaft 653. The oscillatormechanism shaft 603 is journaled in a journal housing 694- which issecured to a mounting bracket 605 that is adjustably mounted and securedto the main frame stand 263 preferably on a $113.11 pad 218 by anyconvenient securing means such as machine screws or bolts 666.

Within the journal housing 696 a pair of bearing members 607 ofappropriate qualities such as frictionless bearings of the ball type orroller type are secured in place and rotatably support the oscillatormechanism shaft 603. The inner race 6% of one of the bearings 667 isseated against a shoulder portion 669 on the shaft 603 and held in placeby a nut 610 threaded onto a small threaded section 611 of the shaft 663having a smaller diameter than the principal remaining section of theshaft 603. At the other end of the shaft 663 it is still furtherenlarged and threaded to provide for seating of the inner race of thesecond bearing 697 and securing of the same to the shaft 603 by anappropriate nut 612. The end of the shaft 603 opposite to the end wherethe pulley 662 is keyed thereto is still further enlarged as at 613, orif it is found convenient an enlarging member such as the portion 613may be secured to that end of the shaft 663, and outwardly therefromthere is carried a slightly eccentric portion 614 which may be either aneccentrically machined portion of the shaft 603 or a roller carried andjournaled on an eccentrically machined portion of the shaft 663 or aroller carried on an eccentrically machined portion of the enlargingmember 613 secured to the shaft 603 as desired or found convenient. Inany event, the shaft 603 is provided at one end thereof, the endopposite to the pulley 662, with an eccentric member 614. Theeccentricity of the member 614 need not be great and in a preferredembodiment of the present invention the eccentricity may be about @1 ofan inch more or less as found convenient. The important feature is thatthis slight eccentricity provides oscillatory movement to the workpieceto prevent surface polishing along a single path thereon, thus avoidingchanneling or grooving due to grit or dirt or the like which may bepresent on the surfaces of the polishing belt. This subject matter willbe further discussed in detail below.

An oscillator block 535 is secured to the side of the main track bedblock 511 of the work holder assembly 5 immediately adjacent to theoscillator mechanism 6. This oscillator block 535 is provided with achannel 535 therethrough having a width about the same, or very slightlygreater than the diameter of the eccentric roller or the like 614. Theeccentric member 61% seats within the channel 535 and upon poweredrotation of the shaft 603 horizontally oscillates the work holderassembly and mechanism 5 thereby pivoting the same about the pivot shaft516. Vertical eccentricity of the member 614 is lost within the channel535'.

From the above it will be understood that upon energizati'on of themotor 201 and the magnetic clutch or the like 211, if the same isprovided to the shaft 216 of the motor 201, the work holder mechanismcarriage 530 will be reciprocated by the reciprocator mechanism 4 andthe whole work holder assembly 5 will be oscillated by the oscillatormechanism 6 about the pivot pin or shaft 516.

The work holder carriage housing 531 is a substantially hollow memberwithin which it carries a jaw mechanism as best viewed in detail inFigure 7.

A workpiece 10 such as a turbine blade or bucket or vane having a fluidguiding blade section 11 and a base 12 is held between a pair of arms orjaws 536 and 537 having jaw inserts 538 and 539, respectively. Thesejaws or arms 536 and 537 are journalcd on bearings or the like 540 and641, respectively, for clamping or releasing rotation of the jaws towardand away from each other at their jaw insert ends. The bearings 54th and541 need be no more than pivot pins provided in a chuck bracket 542 atits lower extremity. The chuck bracket 542 includes a sleeve section 543above the jaws 536 and 537 and is there journaled in bearings 544 and545 the outer races of which are seated against the inner wall of thecarriage housing 531 for rotatable mounting of the workpiece clampingjaws. The bearings 544 and 545 are firmly positioned by a bearing spacer546 positioned therebetween, a bearing retainer ring 547 secured to thelower extremity of the carriage housing 531 and a sleeve member 548threaded onto the upper end of chuck sleeve 543. A shoulder 549 of thechuck sleeve 543 rests against the lower side of the inner race of thebearings 544 also assisting in holding the bearings in proper position.

A pin or rod 550 is slidably fitted through the chuck sleeve 543 so thata lower tapered end 551 thereof is engageable with arcuate upper ends552 and 553 of the jaw members 536 and 537, respectively, in cammingrelation. Immediately above the upper end of the chuck sleeve 543 thepin or rod 550 is provided with a shoulder 554 against which a washer orthe like 555 rests. A compression spring or like biasing member 556rests on the washer 555 and is retained in position about the rod 550 bya spring retaining cup 557 slipped over the upper end of the rod 550 andthreaded onto the sleeve 548.

The spring 556 is thus operably disposed to continuously bias the pin orrod 556 in the direction of the jaw members 536 and 537 so that thetapered lower end 551 of the rod 550 is continuously biased against thecamming upper ends 552 and 553 of the jaw members thereby biasing thejaw members 536 and 537 into a closed clamping locking relation with thebase 12 of the workpiece 10. Raising of the pin 556 through operation ofthe jaw release operator mechanism 7 operates to release the workpiece10 from the jaw members 536 and 537 which are biased apart by a springmember or the like 558 seated in small recesses 559 and 56th in the jawmembers 536 and 537 intermediately between the jaw inserts 538 and 539and the pivot pins 546 and 541.

The worloholding mechanism and assembly 5, specifically, and the wholeturret-type polishing machine 1, generally, is equipped with ajaw-release mechanism 7 for each of the polishing units. The jaw-releasemechansrn 7 for the polishing unit 2a is best illustrated, and may bebest understood, in conjunction with Figures 3, 5, 7, 8 and 9. Beforeundertaking an understanding of the whole jaw-release mechanism andoperator mechanism 7, how ever, the reader should first understand theoperation of the portion of the jaw-release mechanism which forms a partof the work-holding carriage 530. This portion of the jaw-releasemechanism is best viewed in Figures 7, 8 and 9.

A small journal box 56111 is secured to the outer face of the carriagehousing 531 and therein carries a jawrelease mechanism shaft 561journaled in bearings 562 so that the shaft is disposed forwardly of thecarriage housing 531 and transversely thereof. At one side of thecarriage housing 531 and at one end of the shaft 561 a crank handleextending upwardly and rearwardly in the jaw-lock position is pinned orotherwise fixedly secured to the shaft 561 for positive rotation of theshaft with the crank handle 563. As illustrated in Figure 8 the crankhandle 563 fits onto one end of the shaft 561 and is pinned intopositive engagement therewith by a pin member 564.

Intermediate the ends of ithe shaft 561 a leveror the .like

5,65is-keyed onto the shaft- 61-for positive rotationtherewith. Thislever'.565 has.a bifurcated endportion including arms 566 and 567 whichextend around the rod or pin 550 that ,cammingly serves to openorclosethe jaws 536 and 537 of the workvholding mechanism. At the upperend of the rod 550rod-raisingnutmembers 568 threadably engage the rod orpin 550 immediately above the area of therod where the arms 566 and 567of the bifurcated end portion of the lever 565 surround the rod. Thus,it may be seen that rotation of the shaft 561 by manipulation .of thelever handle or crank handle 563 operates to push the ,rod upwardlythereby permitting opening ofthe jaws under the biasing force of thespring .558, thereby releasing and/or ejecting the workpiece 10.'Renotationvof the shaft561 returning the crank handle '563to its normalposition, returns the camming lever 565 toits normal position permittingclosure and locking of thejaws 536 and537by action of the biasing spring556 urgingfthe rod orpin550 downwardly against the arcuate cam endsl52and 553 of the jaws 536 and 537.

In accordance with the principles of the present invention, thepolishing machine 1 is equipped to .release the workpiece held by eachof the polishingunits 2a, 2b, 2c,

"2d and"2e as each approaches an operator station which is a preselectedposition about the general periphery of the machine 1. A preferredembodimentof this mechanismfor automatically releasing or .ejectingtheworkpiece isillustrated in conjunction with thepolishing unit 2a inFigures 1, 3 and Sand is indicated generally by the numeral7. A portionof .the workpiece release operator mechanism "7 is duplicated on eachofthe polishing .units of the machine 1 and another portion thereof issecured to the pedestal or base portion 302 of the turret mechanism 3.Specifically, and as shown on the drawings, a workpiece release operatorcam '701 is secured to the outer peripheral wall of the pedestal section302 near the top thereof and in-the vicinity of the operator station inany convenient manner such as by bolts or'screws or the like afiixingthe same to an "angle ironsupport orthe like 702. The cam 701 is socontoured as to have maximum radial extension in the vicinity of itsleading edge 703 as it isapproached by each polishing unit. Thereafter,for a short distance the cam 701 has a substantially constant radialextension as inithe area 7.04 thereof after which the radialidimensiondiminishes a preselected amount for a substantially greater arcllengthas in the area 705 until the trailing edge offthe cam701'in the vicinityof the end of the operator station. This cam construction may be bestobserved in Figure 5 in elevation and in Figure 1 in invisiblelinejillustration.

.By this construction the cam 701 is provided with a .camrningface 706which controls the operation of the work-release operator mechanism 7.The cam face706 is engagedby a roller'707 which is journaledbetween thearmsof a first bifurcated end portion 708 of a substantially centrallyjournaledlever -709. The lever '709.has

an oifset H shape as edge viewed (Figure 3) and the roller707 isjournale'd on a pin or the'like 710 between the arms 711 and712of theend'708thereof. A control supporting post 713 is secured to the flange206 of the support bracket 203 and oarriesthe lever 709 in a journaledmanner thereon.

The other bifurcated end 714 of a second arm of the lever 709 pivota'llycarries a link'715 which is coupled to a second substantially H-shapedlever 720through a universal coupling unit 716.

This second substantially H-shaped lever '720 is centrally journaled ona pin. or shaft or the like721 on the main track member 511 forsubstantially vertical plane pivotal movement. The universal couplinglinkage 716 interconnects "the lower bifurcated arm 722 of the lever"720 and the arm714of thelever 709 such that horizontal "plane pivotalmovement of'the lever '709 on the post713 imparts vertical 'planepivotalmovement tothe lever 720.

Theiupper bifurcated arm 7239f the lever 7..20,is ,pivorally pinned asat'72.4.to a workyr'elease, operator baf .725. Inthe region of itsopposite endfromits connection ,with the lever720, the-Work-releaseoperatorbarilZS ,,is,;pivotallypinned as at726 to :anotherlever727Which-is also journaled or pinned to themain track memhersllfisat 728for substantially vertical plane pivotal movement.

The levers 720 and 727 cooperateto supportthe release actuator bar 725substantially vertically subhthat,a,leading face 730 thereof, thefrontedgeof the bar"725,,.1ics in a substantially vertical line and inplane movement relation with a roller or the like 731 ,j-ournaled ,infthe free end ofthe work-release, actuator handlefor. craiik563. Thiswork-release operator mechanism (FigurejS) 'islso operative thatengagement of the roller with the camjface 706 in the region704 of thecam'701 pivots the lever-"709 about the post 713 thereby pullingthelower end722 of the lever 720 (Figure"3) rearwardly pivoting thesameabout the pivot 721 and moving the upper Varm723 of the lever720forwardly and'downwardly. 'Thefllever7'27 follows the movement o'ftheupper arm 723 of the lever 720 throughits positivelinkage therewith viathe'bar'725 ing and ejectingihc workpiece 10. Asthe roller'707 rides thecamming face'ififi ofthe'cam701 in the region'704 thereof the jaws 536and 537 are opened to amaximum spacing therebetween thereby permittingtheworkpiece 10 to fall freely therefrom. "The radial dimension "of theregion704 may, of course, be so controlledth'at'the workpiece '10 willmerely be released but will not'fall orbe ejected by virtue ofinsufficient opening of the jaws'5*36 and 537 to permit such ejection.In this preferred embodiment of the present invention,however,thejaws536 .ancl537 are opened'to eject the workpiecelO when theroller 707 rides the cam in the region704 thereof.

As the polishing unit mechanism 2a continues, iniits movement about themaohine las dr'iven'ibythe-turret mechanism 3, the roller 707 leaves'theregion 704 ofthe cam 701 and moves intothe region705 oflesser-radialextensionthereby slightly retracting the release op'erator bar725 and inturn slight retracting the-releaseope'rator handle or crank563 tomovethejaws536 and 537slightly closer together. L In this regionofoperation-the jaws '536 and 537 are separatedby a distancesufiicienttqperniit free insertionor removal of a-newworkpiece 10. Thespacingbetween the jaws'hereis notsufiicientto permit dropping orejection of the workpiece-10 but "is small enough to support theworkpieceltl.

Continued movement 'of thepolishing unit mechanism 2a past the trailingedge of the cam ,701 and out of -the operator station releasesitherelease-operator mechanism from the cam 701 therebyretracting therelease operator bar 725 completely from the release handle or crank563thereby permittingthe pin 550to cammingly wedge between the'upper'ends'of the jaws 536 and 53'7-thus-clamping the workpiece 10 betweenthejaws. The barlZS is retracted under a biasing force providedby anyconvenient means such astabiasingtension spring 7'40ihookedto the'maintrack member 51 1 at one end and tothe' bar725 at its other end.

ative in accordance with the principlesthereof isillustrated in and maybe best understood in conjunction with Figures 3, 4, and 6. The lowerportion of Figure 3 illustrates the polishing surface mechanism 8 inside view, while the lower portion of Figure 4 illustrates the same infront view and Figure 5 is a top elevational view of a portion thereof.Figure 6 is an enlarged front elevational view of a portion of thismechanism.

The polishing surface mechanism 8 includes a pair of retractable,pivotally mounted, polishing head and reel mechanisms 801 and 802 whichare substantially identical to each other and symmetrically arranged toeach present a polishing surface to the workpiece 10. A carriage plate803 secured to the flange portion 2% of the main support bracket 203 andextends substantially across the entire width of the polishing unit 211supporting the several parts and elements of each of the haivcs 3H and892 of the polishing surface mechanism 3.

The polishing surface provided on each of the mechanism sections 801 and802 is provided by training a polishing belt, such as the belts 8M and805 which may be sandpaper or sanding cloth or emery cloth or the like,over a polishing pad 306 and $67, respectively. The polishing pads 8%and (W7 are preferably constructed from a resilient material such as arubber-like material and are mounted on pad brackets 8M and 8G9,respectively, for pivotal movement toward and away from each other andthe workpiece it). For accomplishment of this pivotal movement the padbrackets 808 and W9 have pivot ears or eyelets 810 and 811,respectively, at their lower ends whereat they are journaled on a pin orshaft 812 which is positioned in line with the workpiece iii andworkholding mechanism 5 and secured to the polishing system carriageplate 893.

Since each of the polishing sections 801 and 86 2. are substantiallyidentical in construction and symmetrically assembled, a description ofone of the same, tiull, will operate to describe both thereof. Forsimplicity of ex planation and understanding only the polishingrnechanism section 301 will be referred to for the following detailassembly description.

As stated, the pad bracket ens carries the polishing pad 8% over whichthe polishing surface belt 3% is trained. The pad bracket 398 alsocarries a belt clamp 813 including a stationary lower jaw 614 and aretractable jaw 815. The retractable jaw 815 is formed as a bentlever-like construction pivoted substantially centrally on a pin 816held in the upper reaches of the pad bracket 868. The end of theclamping lever 315 opposite to the actual clamping jaw end thereofcarries a cam roller 817 journaled thereon to rollingly engage apolishing belt clamp-release cam surface 813 on a cam block 819 affixedin its position on the supporting structure. Biasing means such as thecompression spring 820 biases the pivoted jaw arm into clamping relationover the lower jaw 814 and further biases the cam roller 817 intoengagement with the cumming surface $18 of the cam block 819.

The belt-clamping and cam arrangement is so constructed that when thepolishing pad bracket 8% is retracted to the position seen therefor inFigure 6, the jaws are separated from each other and from the polishingbelt 804 through action of the roller 81! riding on the camming surface818. With the polishing pad bracket urging the belt 804 into polishingengagement with the workpiece It), the polishing belt clamping mechanism313 is substantially released from the cam block 819 permitting thespring or the like 820 to urge the jaws of the clamp into clampingrelation. This latter position is seen in the general front assemblyview of Figure 4.

The polishing belt 804 is supplied from a supply reel or the like 830positioned over the cam block 819 and supported for unreeling rotationon a reel bracket 3311 at w an upper eye therein as at 832. In theassembly at the upper eye 832 of the reel-supporting bracket 831 thereel 830 is journaled for rotation and provided with a 12 frictiondragging brake assembly 833 adjustably controlling the drag on the reel830 when the belt 804 is pulled therefrom through operation of thehereinafter described automatic belt polishing surface feed mechanism.

A take-up reel 834 is journaled in the carriage plate 8% somewhat belowthe supply reel 830 and behind the pad carriage bracket 893. The reel834 is also supplied with a hub braking mechanism 835 which isadjustably controlled and prevents free rotation of the take-up reel834.

The polishing belt 804 is supplied from the supply reel 33% with itspolishing surface facing outwardly and is successively trained over apositioning roller 84f) journaled on a small bracket or the like $41immediately behind the polishing pad and belt-clamping jaws, between thebeltclamping jaws are and 815, over the polishing pad 806 which isresiliently urged outwardly, over a second positioning roller $42journaled on the bracket 8'38 adjacent one of the pivot ears 8X6 betweena pair of feed driving rollers 843 and 344 with the roller 844controllably rotated by the belt feed mechanism and the roller 843urging the belt 8% into close engagement with the roller 8% so thatrotation of the roller 844 will operate to move the belt 804longitudinally, and about the hub of the take-up reel 834.

Each of the polishing units, such as the unit 2a, is equipped with anautomatic polishing pad and polishing surface retraction mechanism andpolishing belt feed mechanism 9 which is operable to retract thepolishing pads and pad mounting brackets and to feed a preselectedincrement of the polishing belt forwardly thereby releasing theworkpiece from the polishing unit mechanism 8 and providing a newpolishing surface on the belt over the polishing pad at the operatorstation and at other preselected positions about the periphery of thisturret-type polishing machine 1. The pad-retractor and belt-feedingmechanism 9 is somewhat similar to the automatic workpiece releasemechanism '7 in that it is provided with a cam 9M, Figures 3 and S,secured to the pedestal section 392 of the turret support and extendingperipherally thereabout as seen in invisible line plan View in Figure l.The outer peripheral surface 962 of the earn 981 is the camming surfacecontrolling the operation of the retracting and belt feed mechanism 9and is engaged by a roller or the like 993 journaled in an arm 904 of athree arm lever indicated generally at 905, Figures 3 and 5. The threearm lever 9% is centrally journaled on a pivot post which forconvenience of construction may be a downward extension of the pivotpost 713 of the jawrelease mechanism and operator mechanism '7.

The other two arms 9% and 907 of the three arm lever 95. 5 arediametrically opposite in their extension from the hub center of thelever and are linked by adjustable links 9% and 9%, respectively, toother levers in this retraction and belt-feed mechanism.

As was mentioned above, opposite halves 801 and 802 of the pad assemblyand polishing surface belt mechanism were substantially identical andtherefore only one half, the section Sill, was described in detail inassembly. Similarly, the retraction and belt-feed operator mechanism 9in addition to that part of the same which was described above, includessubstantially identical sections one for each half Sill and 3&2 of thepolishing pad and belt system. Therefore, for purposes of simplicity,only one half will be described, and that half will be in conjunctionwith the section 8%1 described in detail.

The link 9% pivoted for horizontal pivotal movement on the arm 9% of thethree arm lever 9% is pinned at its other end to one arm 91.6 of aretraction lever 911 through a pin or the like 912, Figure 5.

The retraction lever 911 is journaled in the horizontal upper flange ofthe carriage plate 803 for substantially horizontal rotation and at theend of its other arm 912 pivotally carries a universal coupling block913.

A retractor rod 914 is threadably connected or similarly swivelconnector 917 pivotally pinned or the 'like to theuniversal'couplingblock 913 for limited pivotal movement between theears on the arm 912 of the lever "911.

The forked coupling member "917 is mounted for substantially verticalpivotalinovement about a substantially horizontal axis. The limitingmember 915 is provided witha shoulder orthelike "918 between the arms ofthe forked member 917 to seat against the bight section 916 when thefork member is pulled to a retracted position thereby to pu'lltheretracting rod914.

Attire other end ofthe retractingrod914 it is pinned "to a small pivotblock 920 which is in turn pivotally pinned perpendicularly to the padcarriage 808. Abufifer 'spring92l is carried on the retracting rod'914between the forked connector member 917 and a spring compressionadjusting nut 922 threaded onto the rod 914.

The universal coupling block 913 also carries thereunder a feedrodblock930 which is secured thereto by any convenient means such as stud andboltor machine screw or the like 931. The block '930 has a passagetherethrough, not shown, through which passes a belt feeder rod 931. Thepassage through the block930is preferably substantially larger than thediameter of the rod "931 and is still further enlarged on opposite facesof the block 930 to seatingly accept substantially spherically "facedabutment washers 932 and 933 on the rod 931. The feeding rod 931 is alsothreaded for a substantial portion of its length andla pair oflockingnuts934 and 935 "do threadably engage the same and'adjustably retain thespherical faced washer 933 thereon. Behindthe locking nuts934 and 935the threaded end of the rod 3931is substantiallyfree; at its otherendthe rod 931 ispivotally connected to a pivot link936 which isin turnperpendicularly pivotally connected by a pin orthe like to an ear or thelike937 on aplate930 which is journaled on'the shaft939 for the feedroller 844. A buffer spring"940 is carriedbetween the secondsubstantially spherical faced seating washer932 and adjusting nut 941threaded onto the rod931.

The feed roller844 has a serrated disc or wheel or ratchet wheel945'secured thereto for rotation therewith.

The teeth of this ratchet wheel 945 are engagedby a "947' mountedbetween the pawl 946 and aspring backing member 94% mounted on the plate933.

A similar construction at the take-up reel '834 includes a plate950which is journaled about the axis ofthe reel 834 and a serrated discor ratchet wheel1951lmounted for fixed rotation about the axis of thereel834 together with the reel 834. A pawl member 952 is 'pivotallysecured to thelplate 950 and is biased into engagement withthe teeth ofthe ratchet wheel'951 by a spring or the like953 which also engages amountingblock or similar device 954 secured to the plate 950. A link955is pivotally engaged with the plate 938 at one endand 'the'plate950 atthe other end.

As previously pointed out, the other section'802 of the polishingsurface pad and reeling assembly is identically and oppositely equippedwith these above-identified and described retracting and reelinglmembersin proper association. With both of the sections 801 and 802 so equippedand constructed and linked together for equal "and opposite retractionand belt-feeding through engagement with the cam 901 and travelthereacross. Automatic retraction pad members and automatic feeding ofnew increments of the polishing belt maybe efiected at the operatorstation and at otherpreselected positions about the periphery of thisturret-type polishing machine.

The cam 901 with its camming face 902 is so shaped thatas thepolishingunit 2a approaches the operator station about the machine 1, the roller903 onthe lever 905 encounters a region 901a of substantially reducedradial 14 extension on the cam 901. The camroller 903 following,the'surface902 of=theicam901 into the area'901a causes the lever 905 torotate substantially horizontally about the axis of its supporting post,an extension of the post 713, thereby pulling the, links "908 and 909inwardly towards the center olthe polishing unitZa under the .force ofbias spring 905'.

"pawls 946 and 952 "945and951 operate'to-also rotate those ratchetscoun- While the cam roller 903 is riding on the earn 901 at theareathereof whereit is of greatest radial extension, as at With, thepolishing pads are positioned in their closed or actual polishing"positions as viewedfrom the top in Figure 5 and from the front inFigure 4. When the cam roller903 is ridingon the face902 of the caminthe region 9010 thereof, the polishing pads are retracted to theposition seen thereforhin Figure 6; movement of the pads from theposition ofFigures 4 and 5 to the position ofFigure6 is effected whenthe cam roller passes from the area 901b' tothe area1901a and eachsection 801 and802 operates precisely symmetricallylso that only one ofthe same need be described for clarity.

Continuing now with the operation of this system, the

link'908 having been drawn' towards the center of the polishing unit2apivots the lever 911 so that the arm 912 thereoflmovesoutwardlyfrom thecenter of the polishingunit. The arm 912 of the'lever911 movingoutwardly draws with it the retracting .rod914 and the belt feeding rod931. The polishing bracketand its associated parts are drawnbackwardor'retracted with the retracting rod 914' and the cam 'roller'817rolling on the camming surfaceor clamp-release camsurface 818 of theclamp release'cam 819 .opensthegjaws 8l4and 8150f the belt clamp'813.

Atjthe same time, while thebelt feed rod 931 is drawn rearwardly,theplates"938and9'50 are rotated clockwise as viewed in Figure '6.Through this movement of ,the

"plates938 and 950the"pawls"946 and952 are also rotated "tractedfrom'the workpiece "10 and bothof the belts 804- and 805 are releasedfromrtheir associated clamps on "the pad carriages808 and "809. At thistime the feed mechanism is alsococked for feeding a new increment ofthepoliShingbelt to thetpolishing faces of thepads 806 and 807. The beltis fed forwardly and the polishing padsare again urged into polishingengagement withthe 10 as the unit 2a leaves the operator station.

mechanism 5 and a new workpiece Now, as the'unit 2a passes out of theoperatorstation the cam*'roller"903 is again urged outwardly ,by anincrease-in the radial extension of the cam901 (note in visibledottedhline illustration of'cam 901 in'Figure 71) thereby urging thelinkage to the position seen therefor in Figures 4'and 5. 'By effectingthis closure of the pads and pad carriage mechanisms, the plates 93 8and950tare rotated counterclockwise, as viewed in"Figure 6. The engagingthe serrated ratchet plates terclockwise thus. rotating belt-drivingwheel 844 and take- -up"spool"834in a counterclockwise directionpullingthe belt 804 forwardly by a preselected increment from the supplyreel830. The increment .isjpreferably sufficient to present a whole newpolishing surface over theface of the resilient pad 806. At the sametime that the pad .car-

riages808 and 809 are moved to their polishing positions the jaws 815and814iof theclarnp 813i areclosedunder theforce of the biasing member820 and permitted to so 'close by thecam and roller, group 8l9jand 817.

"Toprevent the padsf806 and 807 .frombeingforcedinto too tight anengagement with the work-piece 10, adjustable stop means 850 is providedon the outer face ofithepmain efficiently.

carriage plate 803 between the carriages 808 and 809. The stop means 850preferably carries a pair of adjusta'oly threaded screw and nutcombinations 351 and 852 posttioned as shown in Figures 4 and 6 to buttagainst the facing edges of the carriages 808 and 809.

Adjustment of the stop means 850 may possibly require the carriages 808and 809 to stop prior to completed radial outward movement of the roller903 on the cam 901. The roller 903 is nevertheless permitted fullmovement since the rods 914 and 031 are loosely shock mounted throughtheir appropriate brackets and continued outward movement of the roller903 merely urges the block 930 to shock-absorbing engagement with thespring 940 and the forked member 916 into shock-absorbing engagementwith the spring 021.

This spring-forcing mean also assists in mantaining the polishingsurfaces in resilient engagement with the faces of the workpiece 10, asthe workpiece is reciprocated and oscillated as described above; andpermits selfequalizing of the pressure of the belts and pads against thesurfaces of the workpiece.

In order to insure proper high surface polished finishes to theworkpiece 10 which may be a turbine blade or bucket or vane or the likehaving opposed complex arcuate surfaces, the polishing machine 1 isprovided with means to feed new increments of the polishing belts to thepolishing pads at preselected points along the periphery of the machine.Therefore, cam 901 is provided with additional area of reduced radialextension at spaced points therealong. The particular number of theseareas is not critical, it is preferred that the cam 901 be provided withtwo such areas 9010 and 901d of short arc length and of a radialdimension substantially identical to the radial dimension of the area901a. Note Figure 1. As the polishing unit 2a approaches each of theareas 9010 and 9010! individually, the areas 01c and 901d being spacedapart a distance substantially equal to the distance that they are eachspaced from the operator station, the belt-feeding and pad-retractingmechanism is operated quickly to retract the pads, feed the beltforwardly by a slight increment, and reclose the pads and the twopolishing faces onto the workpiece 10 which may continue to reciprocateand oscillate or which may be stopped by actuation of the magneticclutch or deenergization of the motor 201 as desired.

It should also be noted from Figures 1 and 5 that at the operatorstation the reduced radial extension area 901a of the earn 901 is ofgreater arc length than the arc length of the cam 701 for thework-release operator mechanism and extends in both directions,clockwise and counterclockwise from the end of the cam 701. Thisdimensioning of these earns is provided so that the workpiece polishingpads and polishing surfaces will be retracted from the workpiece priorto stoppage of movement and/ or release of the workpiece by theworkpiece release operator mechanism. In this manner and throughcombined reciprocation and oscillation of the workpiece, the workpieceis polished to a high surface finish without scratches, mars or flawsthereon.

From the above detailed description of the mechanical construction ofthis preferred system embodying the principles of the present inventionand from the described detailed description of the operationalcharacteristics of portions of the machine individually, it will beunderstood that the machine 1 for polishing turbine blades or otherworkpieces is operative to uniformly polish such workpieces rapidly andeconomically. As the turret of the machine rotates, the work-holdingmechanism is reciprocated and oscillated thus reciprocating andoscillating the workpiece thereby avoiding travel of the workpiecethrough a single defined path. By such reciprocation and oscillationsurface mars or scratches due to possible imperfections in the polishingsurface itself, or from such other causes as dirt or grit or the like isavoided most In addition, this turret-type machine is opit"? erative toadvance new polishing surfaces to the workpiece for polishing the sameat a number of points about the periphery of the machine, therebyfurther insuring high surface polishing.

Further, polishing machines embodying the principles of the presentinvention, such as the turret-type polishing machine 1, are operative torelease and/ or eject the workpiece at any preselected position abovethe periphery of the machine which position may be considered as a stopstation or operator station for the machine. The particular work-holdingand ejection mechanism is operative, as described, to eject theworkpiece by opening the jaws the necessary spacing therefor and tothereafter close a sufficient distance to permit insertion of a newworkpiece and hold the same and to still thereafter clamp the same. Thepolishing surfaces of this embodiment of the principles of the presentinvention are retracted from the workpiece before it is released andstopped and are closed upon the new workpiece after it has been clampedfor polishing movement.

It will be understood from the foregoing that numerous modifications andvariations may be made without departing from the true spirit and scopeof the novel concepts of the present invention. 1 therefore do not Wishto be limited to the precise construction shown and described but intendby the appended claims to claim all suchmodifications and variations asfall within the scope of my invention.

I claim as my invention:

l. A polishing machine comprising, a support mechanism, a rotatablemember carried by said support mechanism, a plurality of polishingdevices secured to said rotatable member and rotatable therewith, cammeans secured to said support mechanism, a workpiece holder in each ofsaid polishing devices, workpiece polishing means operably disposed toengage opposite faces of a workpiece held by said holder, means toretract said polishing means from a workpiece, means to release aworkpiece from said holder, first cam follower means to actuate saidretracting means independent of said release means, and second camfollower means to actuate said release means independent of saidretracting means, said cam means and said first and second cam followermeans cooperating to actuate said retracting means prior to actuation ofsaid release means.

2. A polishing machine comprising, a support mechanism, a rotatablemember carried by said support mechanism, a plurality of polishingdevices secured to said rotatable member and rotatable therewith, cammeans secured to said support mechanism, a workpiece holder in each ofsaid polishing devices, mechanism to reciprocate said holder, mechanismto oscillate said holder, workpiece polishing means operably disposed toengage opposite faces of a workpiece held by said holder, means toretract said polishing means from a workpiece, means to release aworkpiece from said holder, first cam follower means to actuate saidretracting means independent of said release means, and second camfollower means to actuate said release means independent of saidretracting means, said cam means and said first and second cam followermeans cooperating to actuate said retracting means prior to actuation ofsaid release means.

3. A polishing machine comprising, a support mechanism, a rotatablemember carried by said support mechanism, a plurality of polishingdevices secured to said r0- tatable member and rotatable therewith, cammeans secured to said support mechanism, a workpiece holder in each ofsaid polishing devices, a pair of resilient pad members, a separatepolishing belt trained over each pad member to provide polishingsurfaces contiguous with said pad members, a supply reel for each belt,-a take-up reel for each belt, means to periodically advance said beltsover said pad members by an increment sufiicient to supply a freshpolish-ing surface thereover, means to retract said polishing surfacesaway from a workpiece in for active said holder, means to release aworkpiece from said workpiece holder, first cam follower means toactuate said retracting means independent of said release means, andsecond cam follower means to actuate said release means independent ofsaid retracting means, said cam means and said first and second camfollower means cooperating to actuate said retracting means prior toactuation of said release means.

4. A polishing machine comprising, a support mechanism, a rotatablemember carried by said support mechanism, a plurality of polishingdevices secured to said rotatable member and rotatable therewith, cammeans se cured to said support mechanism, a workpiece holder in each ofsaid polishing devices, opposed resilient polishing pad members onopposite sides of said holder, a separate polishing belt trained overeach pad member for presenting a pair of opposed polishing surfaces, asupply reel for each belt, a take up reel for each belt, means toperiodically advance said belt including a ratchet and pawl assemblyarranged to drive said take-up reel, means to retract said polishingsurfaces from .a workpiece carried by said holder, means to release aworkpiece from said holder, first cam follower means to actuate saidretracting means independent of said release means, and second camfollower means to actuate said release means independent of saidretracting means, said cam means and said first and second icam followermeans cooperating to actuate said retracting means prior to actuation ofsaid release means.

5. A polishing mechanism for polishing opposed surfaces of a workpiececomprising, a workpiece carrying mechanism, means to simultaneouslyimpart both reciprocatory motion and oscillatory motion to said carryingmechanism, resilient polishing pad member disposed on opposite sides ofa workpiece in said carrying mechanism polishing belts trained over saidpad members respectively polishing by the portions thereof contiguouspad members thereby forming polishing surfaces, and means toperiodically advance said belts past said pad members by incrementssufiicient to position a new polishing portion of the belt thereover.

6. A polishing mechanism for polishing opposed surfaces of an elongatedworkpiece comprising, a workpiece carrying mechanism including a trackmember, a ram member slidably arranged and guided in the track member,mechanism to reciprocate said ram member in the track member, furthermechanism to transversely oscillate said track member and said rammember, a pair of resilient polishing pad members, a polishing belttrained over each of said pad members for active polishing by theportion thereof contiguous with said pad members, a polishing beltsupply reel, a polishing belt take up reel, and means to periodicallyadvance said belts past said pad members by an increment sufficient totrain a new polishing portion of said belt over said pad member, saidmeans to periodically advance said belt including a ratchet and pawlassembly arranged to drive said take-up reel by a preselected increment.

7. In a polishing mechanism operable to polish oppositely disposedcomplex arcuate surfaces of a workpiece, in combination, a pair ofoppositely disposed polishing belts, work-holder means having areleasable jaw mechanism arranged to position a workpiece between saidpolishing belts, mechanism to reciprocate said workholder means, meansto oscillate said work-holder means, a jaw release mechanism, apolishing belt retracting mechanism operable independently of said jawrelease mechanism, and means to actuate said belt retracting mechanismprior to actuation of said jaw release mechanism to retract thepolishing belts from the workpiece prior to release of a workpiece fromthe jaw mechanism.

8. In a polishing mechanism operable to polish oppositely disposedcomplex arcuate surface of a workpiece, in combination, a pair ofoppositely disposed polishing belts,

with said jaw mechanism arranged to position a workpiece between saidpolishing belts, mechanism to reciprocate said jaw mechanism, means tooscillate said jaw mechanism, a jaw release mechanism, a belt retractingmechanism operable independently of said jaw release mechanism, means toactuate said belt retracting mechanism prior to actuation of said jawrelease mechanism to release a workpiece therefrom and to operate saidjaw release mechanism to grip a workpiece prior to return of theretracting mechanism into position to engage the workpiece with thepolishing belts.

9. A turret type polishing machine which comprises a rotatable support,a plurality of polishing units mounted circumferentially around saidsupport, stationary cams disposed around said support, cam followers oneach of said polishing units coacting with said cams, workpiece holderson each of said polishing units, a prime mover on each of said polishingunits to actuate said holders, opposed polishing belts on each unit,means for pressing said belts against opposite faces of a workpiececarried by said holder on each unit, means for retracting said polishingbelts from said workpiece, means for opening and closing said workpieceholder, and said cam followers coacting with said cams to control saidmeans as the rotatable support advances the units around the cam.

10. An automatic polishing machine which comprises a rotatable support,a plurality of polishing units mounted circumferentially around saidsupport, circumferential stationary cams around said support adjacentthe polishing unit on the support, a workpiece holder on each unit,opposed polishing means on opposite sides of a workpiece held by saidholder, means for opening and closing the holder, means for opening andclosing the polishing means, and cam followers on said units coactingwith said cams to control said opening and closing means at preselectedpositions around the work holder.

11. An automatic turret type polishing machine which comprises a carrierrotatable about a vertical axis, a plurality of polishing units mountedon said carrier circumferentially thereof, stationary cams disposedaround said vertical axes adjacent said polishing units, each polishingunit having workpiece carrying jaws and opposed polishing belts foracting on opposite surfaces of a workpiece carried by said jaws, meansfor moving said belt toward and away from a workpiece carried by thejaws, cam follower means coacting with said cams as the units rotatearound the vertical axis on the support for first retracting saidpolishing means, then advancing said polishing belts and thence closingsaid retracting means against the workpiece and additional cam followermeans coacting with said cams for first opening the jaws to discharge aworkpiece, thence partially closing said jaws to permit insertion of anew workpiece and thence completely closing said jaws to clamp theworkpiece.

12. A polishing machine which comprises a rotatable support mechanism, aplurality of polishing units positioned circumferentially about saidsupport mechanism and carried on said support mechanism, stationary cammeans circumferentially fixed to said support mechanism, each of saidpolishing units including a pair of oppositely disposed polishing means,work holding means arranged to position a workpiece between saidpolishing means, a work holding release mechanism, means to retract saidpair of oppositely disposed polishing means from the workpiece, apolishing surface on each of said oppositely disposed polishing means,means to renew said polishing surface, cam follower means coacting withsaid means to retract said polishing means and said cam means to retractsaid polishing means at preselected positions about said supportmechanism and further cam follower means coacting with said cam means tocoact with said means to renew said polishing surfaces at predeterminedpositions circumferentially about said support mechanism.

(References on following page) 19 References Cited in the file of thispatent UNITED STATES PATENTS Re. 16,141 McDonough Aug. 11, 1925 676,700Roper June 18, 1901 1,459,085 Black June 19, 1923 1,490,631 Newkirk, eta1 Apr. 15, 1924 29 .7 Raule' Apr. 25, 1933 Moon June 1, 1937 HamiltonJuly 12, 1938 Indge Nov. 4, 1941 Whitehead Feb. 15, 1949 Dackor et a1Feb. 7, 1951

